Any idea what is a decent house plant to buy my girlfriend? I am looking for something on the larger side that does't require too much looking after.

you can try money plant or Scindapsus aureus. check out the link below.
http://lifeisfresh.blogspot.com/2006/09/money-plant-how-to-grow-and-take-care.html
i got a cutting of the plant from my friend's and soon it grew quite big and it needs little water. twice a week is more than enough. it only needs very little sunlight. i ve kept it in my living room and it looks very nice.